1. Field of the Invention
The present invention relates to a vehicle inner circuit panel with a conducting plastic circuit path, in particular, for use in vehicle panel assemblies such as door and room panel assemblies. Further, the present invention relates to a vehicle panel assembly with the conducting plastic circuit path and to a vehicle panel assembly wiring construction.
2. Description of Prior Art
Conventionally, as shown in FIGS. 7 and 8, wire harnesses 32, 42 (which are produced by bundling a plurality of electric wires) are utilized to supply power to electrical components in the vehicle door 31 and roof 41, respectively.
As shown in FIG. 7, the door wire harness 32, routed to such electrical components as electrically-operated door locks and side view mirrors, extends sinuously in the limited vehicle space to prevent interference with a flashing or sharp edge that occurs around a spot weld. To prevent interference with the flashing, protecting members 33 are also mounted on the wire harness 32. A corrugated tube, polyvinyl chloride sheet (PVC sheet), polyvinyl chloride tube (PVC tube), or acetate tape can be used as the protecting member. For example, FIG. 9 shows a corrugated tube 33 which is mounted as the protecting member on the wire harness 32.
As shown in FIG. 8, the roof wire harness 42 is routed at the back of the ceiling, extending to the operating interior lights such as the dome light 43 and vanity mirror lights 44. The roof harness 42 is fixed at several places by a fixing member such as the tape 45, and extends so that its connectors 46,47 face the openings 48,49 of the roof 41. The respective connectors 46,47 are connected to the operating interior lights 43, 44 through the openings 48,49.
The prior art wiring construction as described above has the following problems.
First, the degree of freedom of design regarding the routing paths of the wire harnesses 32, 42 is limited. It is difficult to set a routing path that involves rapid curves because the wire harnesses 32, 42 are hard to bend. It is also difficult to set a three dimensional routing path because of the limited routing space in the door 31 and roof 41.
Second, the wire harnesses 32, 42 require tight dimensional tolerances for the lengths of main trunks and branches and for the mounting positions of the protecting members 33. It is difficult and cumbersome to maintain the tight dimensional tolerances. Further, the process of fixing the wire harnesses at several places by tape is tedious and inconvenient.
Third, it is tedious and inconvenient to manage the various kinds of protecting members 33. More specifically, it is tedious and inconvenient to select most appropriate protecting members among the various kinds of protecting members, taking into account the flashing and edge conditions and the required degree of soundproofing; and to mount the selected protecting members appropriately.
The present invention has been developed, taking the above problems into account. An object of the present invention is to increase the degree of freedom of design to arrange an electrical circuit path on a vehicle circuit panel such as vehicle door and roof circuit panels, and to improve circuit path forming workability. Another object of the present invention is to eliminate the labor-intensive protecting members.
To solve the above problems, the present invention provides a vehicle inner circuit panel that includes a base member formed of an electrically insulating plastic material and a conducting plastic circuit path formed of an electrically conductive plastic material. The conducting plastic circuit path is formed unitarily with the base member, and is at least partially embedded in the base member, thereby forming a one-piece molded plastic member. Thus, the conducting plastic circuit path is formed into a desired circuit configuration within the base member.
In accordance with this construction of the present invention, the vehicle inner circuit panel can be used as a circuit board. Additionally, the conducting plastic circuit path can be formed into any circuit configuration, thereby eliminating the constraints of location and configuration of the circuit path and thus increasing the degree of freedom of design of the arrangement of the circuit path. Also, the wire harness fixing process can be eliminated, thereby improving productivity significantly. Further, even a tight dimensional tolerance can be readily accommodated with a suitable mold. Finally, since the conducting plastic circuit path is embedded in the base member, it becomes easy to prevent interference with a flashing or a sharp edge, thus eliminating the labor-intensive protecting members.
In another aspect of the present invention, the vehicle inner circuit panel has a contact portion that projects from the conducting plastic circuit path into a socket of a connector housing made of an electrically insulating plastic material. Preferably, the contact portion is a metal contact member formed integrally with the plastic circuit path. For example, the metal contact member may be molded into the conducting plastic circuit path during its manufacture. Alternatively, the metal contact member may be press fit or attached within an opening or a recess of the conducting plastic circuit path. Also, the contact portion may be made of the electrically conductive plastic material and formed unitarily with the circuit path.
In a further aspect of the present invention, the connector housing is formed unitarily with the base member.
In another aspect of the present invention, the vehicle circuit panel has a mounting cover made of a non-conductive hard plastic material and a housing portion made of the non-conductive hard plastic material. The housing portion is formed unitarily with the mounting cover. The mounting cover is mounted on the one-piece molded plastic member, and the contact portion projects into the socket of the housing portion.
In yet another aspect of the present invention, the conducting plastic circuit path is embedded in such a manner as to be generally coplanar with the base member, thereby forming a generally flat surface on the one-piece molded plastic member. The conducting plastic circuit path is exposed on the flat surface. Hence, to cover the exposed circuit path, an electrically insulating cover sheet is mounted on the flat surface. Preferably, the cover sheet is formed of a relatively soft resin, thereby increasing the shock absorption as well as the electrical insulation of the one-piece molded plastic member. Of course, instead of the cover sheet, the mounting cover may be mounted on the flat surface.
Moreover, the present invention provides a vehicle panel assembly that includes a vehicle body panel, an interior trim panel engageable with the vehicle body panel, and a plastic circuit panel disposed between the vehicle body panel and the interior trim panel. The plastic circuit panel has a base member formed of an electrically insulating plastic material and a conducting plastic circuit path formed of an electrically conductive plastic material. An electrical component is mounted on at least one of the three panels, and is configured to be electrically connected to the conducting plastic circuit path. Preferably, the plastic circuit panel is a one-piece member formed by molding the circuit path unitarily with the base member, whereby the plastic circuit path is formed into a desired circuit configuration.
In another aspect of the present invention, the plastic circuit panel has a first connector which is connected to the conducting plastic circuit path and which is configured for engagement with a mating connector of an outer wire harness that extends from outside the vehicle body panel. Thus, the plastic circuit path can be readily connected to the outer wire harness upon engagement of the first and mating connectors. The plastic circuit panel further has a second connector which is connected to the conducting plastic circuit path and which is configured for engagement with a component side connector of an inner wiring member that extends from the electrical component. Thus, upon engagement of the second and component side connectors, the circuit path can be readily connected to the electrical component. Therefore, the outer wire harness can be connected to the electrical component.
Furthermore, the present invention provides a vehicle panel assembly wiring construction for supplying power to the above vehicle panel assembly. In addition to the vehicle body panel, the wiring construction includes an outer wire harness that extends from outside the vehicle body panel to supply power to the electrical component. The outer wire harness has a power supply side connector which is connected to an end thereof and which is engageable with the first connector connected to the conducting plastic circuit path at one end thereof. The wiring construction further includes an inner wire harness that extends from the electrical component to the second connector which is connected to the plastic circuit path at the other end thereof The inner wire harness has an electrical component side connector which is connected to an end thereof and which is engageable with the second connector. The first and second connectors are respectively coupled to the power supply side and electrical component side connectors. Consequently, the outer wire harness is electrically connected to the electrical component through the conducting plastic circuit path and the inner wire harness, thereby supplying power to the electrical component.
The term xe2x80x9cvehicle body panelxe2x80x9d used herein includes, but is not limited to a door body panel, a roof body panel, a floor body panel and a firewall.
The term xe2x80x9cinterior trim panelxe2x80x9d used herein includes, but is not limited to a door interior trim panel, a roof interior trim panel, an interior floor carpet, an instrumental panel and a center cluster panel.
The term xe2x80x9celectrical componentxe2x80x9d used herein includes, but is not limited to electrical devices such as electrically-operated door lock, power window, side view mirror and operating interior light devices which are disposed between the vehicle body panel and interior trim panel or which are disposed on at least one of the vehicle body panel, interior trim panel and plastic circuit panel.
The term xe2x80x9celectrically conductive plastic materialxe2x80x9d used herein includes, but is not limited to a high conductivity resin composition which can be formed as disclosed in Japanese Unexamined Patent Publication Nos. Hei 10-237331 and Hei 11-342522, for example, by:
(a) blending metallic fiber such as copper, nickel and iron (singly or in combination) into thermoplastic resin, or
(b) blending a low melting point alloy such as solder (low melting point solder), along with Cu powder, into thermoplastic resin, and dispersing them to cross-link.
For the thermoplastic resin, polypropylene, polyethylene, polystyrene, polyacrylonitrile-butadiene-styrene, modified polyphenylene oxide, polybutyleneterephthalate, polyethyleneterephthalate, polyamide, aromatic polyamide, polyphenylenesulfide, liquid crystal polymer, polyetherimide, polybenzimidazole, polyetherketone and polyethersulfone, in particular, can be used, either singly or in combination, to form the electrically conductive plastic material. Particularly preferred resins are acrylonitrile-butadiene-styrene and polybutyleneterephthalate.
The low melting point alloy, which is blended to be dispersed to cross-link in the thermoplastic resin, should be of the kind with a melting point of more than 100 degrees, preferably more than 200 degrees, and which melts well during injection molding. For example, Snxe2x80x94Pb, Snxe2x80x94Agxe2x80x94Pb, Snxe2x80x94Bi, Snxe2x80x94Bixe2x80x94In, Bixe2x80x94Pb, Bixe2x80x94Sn, Snxe2x80x94Cu, Snxe2x80x94Cuxe2x80x94Nixe2x80x94Pb, Snxe2x80x94Ag, Snxe2x80x94Bixe2x80x94Pb and Snxe2x80x94In based alloys may be suitable for the purpose of the present invention. Lead-free solder is a particularly preferred low melting point alloy.
Alternatively, the electrically conductive plastic materials such as those described in U.S. Pat. No. 5,685,632 and U.S. Pat. No. 6,216,671 can be used for the purpose of the present invention. Of course, any suitable electrically conductive plastic materials which are formed from plastic materials other than those described above or disclosed in the above U.S. and Japanese publications, can also be used for the purpose of the present invention and will fall within the intended scope of the present invention.
With respect to the electrically insulating plastic material, conventional thermoplastic and thermosetting resins can be used to form, for example, the base member, the insulating cover and the housing of the present invention.